neesenk

static char ffslut32[] = {
	32,  1, 23,  2, 29, 24, 14,  3, 30, 27, 25, 18, 20, 15, 10,  4,
	31, 22, 28, 13, 26, 17, 19,  9, 21, 12, 16,  8, 11,  7,  6,  5
};

static char ffslut64[] = {
	64,  1, 48,  2, 57, 49, 28,  3, 61, 58, 50, 42, 38, 29, 17,  4,
	62, 55, 59, 36, 53, 51, 43, 22, 45, 39, 33, 30, 24, 18, 12,  5,
	63, 47, 56, 27, 60, 41, 37, 16, 54, 35, 52, 21, 44, 32, 23, 11,

neesenk

/* 0000000: 0000 0000 0000 0000 0000 0000 0000 0000  ................ */
void hexdump(const char *buff, int blen)
{
	static char hexmap[] = "0123456789abcdef";
	int offset, len, count, hexoff;
	unsigned char str[58], c;
	str[57] = 0, str[40] = ' ';
	for (offset = 0, len = 16; offset < blen; offset += 16) {
		if (blen - offset < 16) {
			len = blen - offset;

neesenk

#ifndef __DYNAMINC_ARRAY_H__
#define __DYNAMINC_ARRAY_H__

#include <string.h>
#include <stdlib.h>
#include <assert.h>

#ifdef __cplusplus
extern "C" {
#endif

neesenk

char *strtrim(char *str)
{
	size_t len;
	char *pb;
	for (pb = str; isspace(*pb); pb++); /* isspace(0) == 0 */
	for (len = strlen(pb); len > 0 && isspace(pb[len - 1]); len--);
	if (pb > str && len > 0)
		memmove(str, pb, len);
	str[len] = 0;
	return str;

neesenk

/* 输出[0..n-1]的一个随机子集m */
void randselect(int *a, int m, int n)
{
	while (m > 0) {
		if (random() % n-- < m)
			a[--m] = n;
	}
}

neesenk

/* 编译时断言, cond为编译时常量 */
#define BUILD_ASSERT(cond) do { (void) sizeof(char [1 - 2*!(cond)]); } while(0)
#define EXPR_BUILD_ASSERT(cond) (sizeof(char [1 - 2*!(cond)]) - 1)

/* 数据类型的对齐方式 == __alignof__(t) */
#define ALIGNOF(t) ((char *)(&((struct { char c; t _h; } *)0)->_h) - (char *)0)

#define container_of(ptr, type, member)				\
	((type *)((char *)(ptr) - (size_t)(&((type *)0)->member)))

neesenk

#include <assert.h>

static inline int prefix_cmp(char *prefix, char *str)
{
	unsigned char *p = (unsigned char *)prefix;
	unsigned char *s = (unsigned char *)str;
	while (*p && *s && *p == *s)
		p++, s++;

	return (*p == 0) ? 0 : *p - *s;

neesenk

#include <stddef.h>

#define TYPE_SWAP(a,b) do { TYPE t = (a); (a) = (b); (b) = t; } while (0)
static inline void _reverse(TYPE *base, size_t n)
{
	size_t i = 0;
	for (i = 0; i < n/2; i++)
		TYPE_SWAP(base[i], base[n - i - 1]);
}

neesenk

/**
 * js前端的模版
 * zhiyongliu <zhiyongliu@tencent.com>
 *
 * 支持两种指令: <!-- -->, <!--{}-->
 * 1. <!-- --> js的控制结构的代码；不包含输出
 * 2. <!--{}--> 输出的内容, 结果为string或可转换为string的表达式
 */
var MyTemplate = MyTemplate || function(id) {
        var analyze = function (str) {

hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs